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/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import org.checkerframework.checker.nullness.compatqual.NullableDecl;

/**
 * Implementation of {@code Multimap} whose keys and values are ordered by their natural ordering or
 * by supplied comparators. In all cases, this implementation uses {@link Comparable#compareTo} or
 * {@link Comparator#compare} instead of {@link Object#equals} to determine equivalence of
 * instances.
 *
 * 

Warning: The comparators or comparables used must be consistent with equals as * explained by the {@link Comparable} class specification. Otherwise, the resulting multiset will * violate the general contract of {@link SetMultimap}, which is specified in terms of {@link * Object#equals}. * *

The collections returned by {@code keySet} and {@code asMap} iterate through the keys * according to the key comparator ordering or the natural ordering of the keys. Similarly, {@code * get}, {@code removeAll}, and {@code replaceValues} return collections that iterate through the * values according to the value comparator ordering or the natural ordering of the values. The * collections generated by {@code entries}, {@code keys}, and {@code values} iterate across the * keys according to the above key ordering, and for each key they iterate across the values * according to the value ordering. * *

The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an * existing key-value pair has no effect. * *

Null keys and values are permitted (provided, of course, that the respective comparators * support them). All optional multimap methods are supported, and all returned views are * modifiable. * *

This class is not threadsafe when any concurrent operations update the multimap. Concurrent * read operations will work correctly. To allow concurrent update operations, wrap your multimap * with a call to {@link Multimaps#synchronizedSortedSetMultimap}. * *

See the Guava User Guide article on {@code * Multimap}. * * @author Jared Levy * @author Louis Wasserman * @since 2.0 */ @GwtCompatible(serializable = true, emulated = true) public class TreeMultimap extends AbstractSortedKeySortedSetMultimap { private transient Comparator keyComparator; private transient Comparator valueComparator; /** * Creates an empty {@code TreeMultimap} ordered by the natural ordering of its keys and values. */ public static TreeMultimap create() { return new TreeMultimap<>(Ordering.natural(), Ordering.natural()); } /** * Creates an empty {@code TreeMultimap} instance using explicit comparators. Neither comparator * may be null; use {@link Ordering#natural()} to specify natural order. * * @param keyComparator the comparator that determines the key ordering * @param valueComparator the comparator that determines the value ordering */ public static TreeMultimap create( Comparator keyComparator, Comparator valueComparator) { return new TreeMultimap<>(checkNotNull(keyComparator), checkNotNull(valueComparator)); } /** * Constructs a {@code TreeMultimap}, ordered by the natural ordering of its keys and values, with * the same mappings as the specified multimap. * * @param multimap the multimap whose contents are copied to this multimap */ public static TreeMultimap create( Multimap multimap) { return new TreeMultimap<>(Ordering.natural(), Ordering.natural(), multimap); } TreeMultimap(Comparator keyComparator, Comparator valueComparator) { super(new TreeMap>(keyComparator)); this.keyComparator = keyComparator; this.valueComparator = valueComparator; } private TreeMultimap( Comparator keyComparator, Comparator valueComparator, Multimap multimap) { this(keyComparator, valueComparator); putAll(multimap); } @Override Map> createAsMap() { return createMaybeNavigableAsMap(); } /** * {@inheritDoc} * *

Creates an empty {@code TreeSet} for a collection of values for one key. * * @return a new {@code TreeSet} containing a collection of values for one key */ @Override SortedSet createCollection() { return new TreeSet(valueComparator); } @Override Collection createCollection(@NullableDecl K key) { if (key == null) { keyComparator().compare(key, key); } return super.createCollection(key); } /** * Returns the comparator that orders the multimap keys. * * @deprecated Use {@code ((NavigableSet) multimap.keySet()).comparator()} instead. */ @Deprecated public Comparator keyComparator() { return keyComparator; } @Override public Comparator valueComparator() { return valueComparator; } /** @since 14.0 (present with return type {@code SortedSet} since 2.0) */ @Override @GwtIncompatible // NavigableSet public NavigableSet get(@NullableDecl K key) { return (NavigableSet) super.get(key); } /** * {@inheritDoc} * *

Because a {@code TreeMultimap} has unique sorted keys, this method returns a {@link * NavigableSet}, instead of the {@link java.util.Set} specified in the {@link Multimap} * interface. * * @since 14.0 (present with return type {@code SortedSet} since 2.0) */ @Override public NavigableSet keySet() { return (NavigableSet) super.keySet(); } /** * {@inheritDoc} * *

Because a {@code TreeMultimap} has unique sorted keys, this method returns a {@link * NavigableMap}, instead of the {@link java.util.Map} specified in the {@link Multimap} * interface. * * @since 14.0 (present with return type {@code SortedMap} since 2.0) */ @Override public NavigableMap> asMap() { return (NavigableMap>) super.asMap(); } /** * @serialData key comparator, value comparator, number of distinct keys, and then for each * distinct key: the key, number of values for that key, and key values */ @GwtIncompatible // java.io.ObjectOutputStream private void writeObject(ObjectOutputStream stream) throws IOException { stream.defaultWriteObject(); stream.writeObject(keyComparator()); stream.writeObject(valueComparator()); Serialization.writeMultimap(this, stream); } @GwtIncompatible // java.io.ObjectInputStream @SuppressWarnings("unchecked") // reading data stored by writeObject private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException { stream.defaultReadObject(); keyComparator = checkNotNull((Comparator) stream.readObject()); valueComparator = checkNotNull((Comparator) stream.readObject()); setMap(new TreeMap>(keyComparator)); Serialization.populateMultimap(this, stream); } @GwtIncompatible // not needed in emulated source private static final long serialVersionUID = 0; }





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